Fine and Coarse Carbonaceous Aerosol in Houston, TX, during DISCOVER-AQ

To investigate major sources and trends of particulate pollution in Houston, total suspended particulate (TSP) and fine particulate matter (PM<sub>2.5</sub>) samples were collected and analyzed. Characterization of organic (OC) and elemental (EC) carbon combined with realtime black carbo...

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Main Authors: Subin Yoon, Sascha Usenko, Rebecca J. Sheesley
Format: Article
Language:English
Published: MDPI AG 2020-05-01
Series:Atmosphere
Subjects:
Online Access:https://www.mdpi.com/2073-4433/11/5/482
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author Subin Yoon
Sascha Usenko
Rebecca J. Sheesley
author_facet Subin Yoon
Sascha Usenko
Rebecca J. Sheesley
author_sort Subin Yoon
collection DOAJ
description To investigate major sources and trends of particulate pollution in Houston, total suspended particulate (TSP) and fine particulate matter (PM<sub>2.5</sub>) samples were collected and analyzed. Characterization of organic (OC) and elemental (EC) carbon combined with realtime black carbon (BC) concentration provided insight into the temporal trends of PM<sub>2.5</sub> and coarse PM (subtraction of PM<sub>2.5</sub> from TSP) during the Deriving Information on Surface Conditions from Column and VERtically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) Campaign in Houston in 2013. Ambient OC, EC, and BC concentrations were highest in the morning, likely due to motor vehicle exhaust emissions associated with the morning rush hour. The morning periods also had the lowest OC to EC ratios, indicative of primary combustion sources. Houston also had significant coarse EC at the downtown site, with an average (±standard deviation) PM<sub>2.5</sub> to TSP ratio of 0.52 ± 0.18 and an average coarse EC concentration of 0.44 ± 0.24 µg·C·m<sup>−3</sup>. The coarse EC concentrations were likely associated with less efficient industrial combustion processes from industry near downtown Houston. During the last week (20–28 September, 2013), increases in OC and EC concentrations were predominantly in the fine fraction. Both PM<sub>2.5</sub> and TSP samples from the last week were further analyzed using radiocarbon analysis. Houston’s carbonaceous aerosol was determined to be largely from contemporary sources for both size fractions; however, PM<sub>2.5</sub> had less impact from fossil sources. There was an increasing trend in fossil carbon during a period with the highest carbonaceous aerosol concentrations (September 24 night and 25 day) that was observed in both the PM<sub>2.5</sub> and TSP. Overall, this study provided insight into the sources and trends of both fine and coarse PM in a large urban U.S. city impacted by a combination of urban, industrial, and biogenic emissions sources.
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spelling doaj.art-4f7f2f6d7f104d2193ce1c769cb286372023-11-19T23:52:51ZengMDPI AGAtmosphere2073-44332020-05-0111548210.3390/atmos11050482Fine and Coarse Carbonaceous Aerosol in Houston, TX, during DISCOVER-AQSubin Yoon0Sascha Usenko1Rebecca J. Sheesley2Department of Earth and Atmospheric Sciences, University of Houston, Houston, TX 77004, USADepartment of Environmental Science, Baylor University, Waco, TX 76706, USADepartment of Environmental Science, Baylor University, Waco, TX 76706, USATo investigate major sources and trends of particulate pollution in Houston, total suspended particulate (TSP) and fine particulate matter (PM<sub>2.5</sub>) samples were collected and analyzed. Characterization of organic (OC) and elemental (EC) carbon combined with realtime black carbon (BC) concentration provided insight into the temporal trends of PM<sub>2.5</sub> and coarse PM (subtraction of PM<sub>2.5</sub> from TSP) during the Deriving Information on Surface Conditions from Column and VERtically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) Campaign in Houston in 2013. Ambient OC, EC, and BC concentrations were highest in the morning, likely due to motor vehicle exhaust emissions associated with the morning rush hour. The morning periods also had the lowest OC to EC ratios, indicative of primary combustion sources. Houston also had significant coarse EC at the downtown site, with an average (±standard deviation) PM<sub>2.5</sub> to TSP ratio of 0.52 ± 0.18 and an average coarse EC concentration of 0.44 ± 0.24 µg·C·m<sup>−3</sup>. The coarse EC concentrations were likely associated with less efficient industrial combustion processes from industry near downtown Houston. During the last week (20–28 September, 2013), increases in OC and EC concentrations were predominantly in the fine fraction. Both PM<sub>2.5</sub> and TSP samples from the last week were further analyzed using radiocarbon analysis. Houston’s carbonaceous aerosol was determined to be largely from contemporary sources for both size fractions; however, PM<sub>2.5</sub> had less impact from fossil sources. There was an increasing trend in fossil carbon during a period with the highest carbonaceous aerosol concentrations (September 24 night and 25 day) that was observed in both the PM<sub>2.5</sub> and TSP. Overall, this study provided insight into the sources and trends of both fine and coarse PM in a large urban U.S. city impacted by a combination of urban, industrial, and biogenic emissions sources.https://www.mdpi.com/2073-4433/11/5/482radiocarboncarbonaceous aerosolurban air qualityblack carbonaethalometer
spellingShingle Subin Yoon
Sascha Usenko
Rebecca J. Sheesley
Fine and Coarse Carbonaceous Aerosol in Houston, TX, during DISCOVER-AQ
Atmosphere
radiocarbon
carbonaceous aerosol
urban air quality
black carbon
aethalometer
title Fine and Coarse Carbonaceous Aerosol in Houston, TX, during DISCOVER-AQ
title_full Fine and Coarse Carbonaceous Aerosol in Houston, TX, during DISCOVER-AQ
title_fullStr Fine and Coarse Carbonaceous Aerosol in Houston, TX, during DISCOVER-AQ
title_full_unstemmed Fine and Coarse Carbonaceous Aerosol in Houston, TX, during DISCOVER-AQ
title_short Fine and Coarse Carbonaceous Aerosol in Houston, TX, during DISCOVER-AQ
title_sort fine and coarse carbonaceous aerosol in houston tx during discover aq
topic radiocarbon
carbonaceous aerosol
urban air quality
black carbon
aethalometer
url https://www.mdpi.com/2073-4433/11/5/482
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